Method of manufacturing racket frames



H. D. PENNEY 10mm or muumc'rumne mm Pawns Original Filed Feb. 16 1923 Patented Dec. 25, 1928.

UNITED STATES PATENT OFFICE.

HAROLD D. PENNEY, OF PELHAM, NEW YORK, ASSIGNOB TO .A, G. SPALDING Ec 3308.,

OF NEW YORK, N. Y., A CORPORATION OF JERSEY.

METHOD OF MANUFACTURING RACKET FRAMES.

Original application filed February 16, 1923, Serial No. 619,413. Divided and this application filed February 4, 1926.

This is a division of application Serial No. 619,413 filed February 16, 1923, now Patent No. 1,588,140, dated June 8, 1926. The mvention relates to the method of manufacture of hollow metal frames, wherein the frame ends form'the base portion of the handle, the frame being bent to form a loop of suitable shape and provided with means for stringing the loop with a suitable material for providing a striking surface.

The object of the invention is to provide an improved method. of manufacture whereby great strength combined with the necessary flexibility and proper weight are nnparted to the frame.

Another object is to provide an implement of the character mentioned with a frame of tubing formed in a cross section such as to impart added strength to the frame,

Another object is to provide an implement of the character mentioned having. a frame of tubing, the tubing being indented to provide opposed concave walls and flattened to provide opposed straight walls, the material of the tubing being incidentally worked during the indenting and flattening whereby greater strength and ri idity of the tubing is afforded.

Reference will now be had to the accompanying drawings for a more detailed description of the device, in which:

Figure 1 is a plan view, partly in section of the frame member.

Figure 2 is a section on line 22 of Figure 1 and looking in the direction of the arrows.

Figure 3 is a section on line 33 of Figure 1 and looking in the direction of the arrows.

A tube a of a suitable metal, preferably a light metal such as magnesium is provided in desirable racket frame length, and substantially of rectangular cross sectional area. The tube length is then bent into a racket form of suitable pattern.

When the frame has reached this form the metal is not stiff enough to make a rigid frame, and in the case of certain metals, which cannot be tempered like forms of other metals by heat treatment, it becomes necessary to work the metal in order to give it the necessary stiffness.

Serial No. 85,882;

This is accomplished by taking the frame of rectangular tubing and indenting it as seen at Z) and c. The indenting is done on the entire outer side as at band on the opposite side as. seen at c. The squeezing action incident tothis indenting causes the other twosides of the tube to bulge, the act of indentin thus resulting in-manipu lating all four sides of the tube. a

The bulging sides of the tubing are then rolled between rolls and flattened back again as indicated at d and e and this action fur ther reworksthe two bulged sides, so that the manipulation of the magnesium metal sets up crystallizing strains which tend to reset the molecules of the metal within the frame or tube and cause the tube to become much stiffer laterally than when the metal is in its natural or normal condition.

It will, therefore, be noted that a frame 7" such as (t is provided which is made strong and rigid in a transverse plane, first, by the indenting of the sides in which form greater strength is provided, and secondly, by causing the metal within the frame to be worked, thereby setting up hardening strains; so that the final article is very much stiffer than it would be if the tube were left in its original unworked condition. The resulting frame thus has concave outer and inner sides and straight or flat upper and under sides.

WVhile the specific form disclosed has been described as substantially of rectangular cross section, it is to be understood that it may be any other form, such as elliptical, without departing from the scope of this invention.

l Vhat I claim is:

1. The method of making astriking implement comprising bending a length of tubing of substantially rectangular cross-sec-v tional area to form the frame of the imple- 'ment of desired shape, the tubing being of metal not susceptible of tempering by heat treatment, indenting the tubing on opposed sides to provide channels thereon, and fiattening the other-opposed sides of the tubing thereby working the metal to provide requisite stiffness.

2. The method of making a. striking implement comprising bending a length of magnesium tubing of substantially rectangular cross-seotional area to form the 5 frame of a, striking implement of desired shape, indenting the tubing on opposed sides to provide channels thereon, and flattening the other opposed sides of the tubing thereby working the metal to provide requisite stiffness. 10

This specification signed this 2nd day of February, A. D. 1926.

HAROLD D, PENNEY. 

